The present invention relates generally to the art of vehicle suspension. More specifically, it relates to an assembly for use in the front suspensions of large vehicles, which includes a leaf spring assembly, a shock absorber, a hanger guide, and an air cushion assembly attached to the front axle of a large over the road truck.
The art of building suspensions in land transport vehicles is fairly old and very well known. Inventors hundreds of years ago bouncing around in buckboard wagons first identified the need for and designed the earliest forms of land transport suspension. The earliest production motor vehicles carried suspension systems and railroad cars carried suspension systems even before motor vehicles. However, no suspension systems of which this inventor is aware employ such a unique combination of simple elements to improve the ride characteristics of large vehicles, specifically, large trucks.
Rough ride, vehicle deterioration, cargo damage and operator fatigue all result from the almost continuous shock and vibration that is transmitted from the road to the vehicle when it is in motion. A particular problem occurring with prior suspension systems is that of operator fatigue. Long periods of vibration caused by irregular surfaces and jolts from bumps in the road contribute greatly to operator fatigue, and may, over time even cause debilitating injuries to operators.
Previous suspension assemblies employ steel and composite springs to dampen vibration and bumps. A problem with these assemblies is that the springs must be designed to carry the maximum load of the vehicle. Therefore, when a truck is empty or only partially loaded, the suspension systems are too stiff to allow the amount or degree of suspension deflection that is necessary to prevent vibration and shock from being transmitted from the road.
Generally speaking, the endurance and load carrying capacity requirements of trucks overshadow the requirements of the operators of the truck. This inventor has however, recognized the necessity of an improvement in the art of truck design that reduces the translation of vibration and bumps to the operator of the vehicle.
Air cushioned suspensions have evolved to address many of the problems associated with the varying loads accommodated by over the road vehicles. However, this inventor is not aware of any improvements using air cushioned suspension systems on the front axle of a truck for improved operator comfort. The device of the present invention improves driver comfort by providing an air cushioned assembly to dampen vibration and surface irregularities.
Another problem of prior suspension assemblies that are used on the front axle of large trucks is that they have no mechanism to prevent sway. The device of the present invention provides a pair of vertically disposed guides in which the leaf springs may travel up and down and a crosspiece that connects one guide to the other. Combined, these two components reduce the amount of sway the driver of the truck experiences.
It is therefore a principal object of the present invention to provide a new, useful and uncomplicated assembly that improves operator comfort by reducing vibration, increasing spring deflection and reducing sway without detriment to the vehicle""s load carrying ability. It is also an object of the present invention to employ air cushion technology in the front axle of large trucks. It is a further object of the present invention to provide such a device that can be easily installed on existing trucks and on new trucks. It is a yet another object of the present invention to provide a xe2x80x9cbolt-onxe2x80x9d device so that operators may retrofit their vehicles for improved comfort. It is also an object of the present invention to provide an apparatus that can be easily manufactured and that can be made with a minimum number of parts.
The device of the present invention obtains these objects. The device of the present invention provides for a front suspension assembly that absorbs vibration, reduces the impact of road irregularities on the operator of the vehicle and reduces vehicle sway. The device of the present invention does not reduce the vehicle""s carrying capacity, is easily installed and is comprised of readily available parts. In order to meet these objects, the device of the present invention provides a pair leaf springs mounted on opposite sides of the frame of the truck at the front and extending backwardly from the front of the truck, a pair of vertically disposed guides extending down from the frame and providing an aperture through which a leaf spring runs, a pair of shock absorbers extending downwardly from the frame of the truck to below the leaf springs and supporting the leaf springs, and a pair of air cushion assemblies each having a bottom attached to the top of the back of one of the leaf springs and a top attached to the frame of a truck. Lastly, the device of the present invention provides a simple assembly of only a few new parts and requires little maintenance. The foregoing and other features of the device of the present invention will be further apparent from the detailed description that follows.